Utilizing high resolution two-dimensional gel electrophoresis we will identify the function of as many of the nuclear nonhistone proteins (NHP) as possible. Based on experience with over 4,000 2-dimensional gels we have modified the procedure so it separates on 20 x 20 cm gels up to 1,000 micron g of non-radioisotope labeled proteins solubilized in 2 percent SDS, 5 percent beta-mercaptoethanol. Isolated NHP of known function or source, such as nuclear membranes nuclear matrix, nucleoli, cytosol, HnRNA proteins, RNA polymerase, contractile proteins and others will be identified in relation to all NHP. This will allow identification of those proteins which are truly tissue specific and may play a role in gene regulation and previously unknown proteins which may play a role in chromosome packaging, HnRNA processing, homologous chromosome pairing, X-chromosome inactivation, coarse and fine gene regulation. A specific nuclear protein, J2, which binds to histone has been isolated in milligram quantities. It will be sequenced and its possible role in altering histone-DNA interaction examined. Finally, a new procedure of spreading isolated chromosomes for electron microscopy suggests the DNA is arranged in a rosette-interrosett pattern. The amount of DNA in the rosettes is similar to that in Drosophila chromomers. These will be examined further to determine whether they represent a true functional unit of chromosome structure.